caa a22 4500 477133363 CHVBK 20180405111710.0 cr unu---uuuuu 170330e19970301xx s 000 0 eng 10.1023/A:1002998216465 doi (NATIONALLICENCE)springer-10.1023/A:1002998216465 Inheritance of resistance to the papaya ringspot virus-watermelon strain from two different accessions of winter squash Cucurbita maxima Duch [Elektronische Daten] [W.R. Maluf, J.J. Pereira, A.R. Figueira] Inheritance of resistance to the papaya ringspot virus-watermelon strain (= PRSV-W, syn. watermelon mosaic virus-1 = WMV-1) was studied for two Cucurbita maxima accessions - ABL-010 and Redlands Trailblazer - considered to be resistant to the potyvirus. ABL-010 (ABL) derives its resistance from Brazilian accessions of C. maxima. Redlands Trailblazer (RT) is an Australian cultivar of C. maxima, the resistance of which traces back to C. ecuadorensis. In both cases, virus could be recovered from the inoculated (symptomless) plants via back inoculation onto susceptible C. pepo cultivar Caserta, indicating a tolerance type of resistance. Both ABL and RT were crossed to each other and to the standard PRSV-W-susceptible cultivar Buttercup (B). For each one of the crosses (ABL ×> B), (ABL × RT) and (RT × B), parental lines, F1, F2 and backcrosses to both the parents (BC1P1 and BC1P2) were tested for PRSV-W resistance after mechanical inoculation. Seedlings were inoculated at the first true leaf stage with a known PRSV-W isolate in 0.02 M phosphate buffer (pH 7.0) plus sodium sulphite 0.01%. Plants were scored for virus symptoms 28 days after inoculation; symptom severity being rated with a scale from 0 (= no symptoms) to 5 (= plants with severe mosaic and leaf distortions). Broad and narrow-sense heritabilities of PRSV-W resistance were 0.44/0.36, 0.59/0.59 and 0.58/0.58 for crosses (ABL × B), (ABL × RT) and (RT × B), respectively. Resistance imparted by ABL in cross with susceptible B could be explained by the action of three genes with partial dominance. Resistance imparted by RT in cross with B was found to be under control of at least two genes with additive effects. Susceptible plants were found in segregating populations of the cross ABL × RT (transgressive segregation), indicating that at least one of the loci involved in the control of resistance in ABL was not allelic to their counterpart loci in RT. The resistance imparted by RT appears to be of higher level than that imparted by ABL. Kluwer Academic Publishers, 1997 squash nationallicence resistance to virus nationallicence potyvirus nationallicence WMV-1 nationallicence PRSV-W nationallicence Cucurbita maxima nationallicence Cucurbita ecuadorensis nationallicence heritability nationallicence degree of dominance nationallicence number of genes nationallicence Maluf W.R. Departamento de Agricultura, Brazil aut Pereira J.J. Departamento de Fitossanidade, Universidade Federal de Lavras, Cx. Postal 37, CEP 37200-000, Lavras - MG, Brazil aut Figueira A.R. Departamento de Fitossanidade, Universidade Federal de Lavras, Cx. Postal 37, CEP 37200-000, Lavras - MG, Brazil aut Euphytica Kluwer Academic Publishers 94/2(1997-03-01), 163-168 0014-2336 94:2<163 1997 94 10681 https://doi.org/10.1023/A:1002998216465 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1002998216465 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Maluf W.R. Departamento de Agricultura, Brazil aut NATIONALLICENCE 700 1- Pereira J.J. Departamento de Fitossanidade, Universidade Federal de Lavras, Cx. Postal 37, CEP 37200-000, Lavras - MG, Brazil aut NATIONALLICENCE 700 1- Figueira A.R. Departamento de Fitossanidade, Universidade Federal de Lavras, Cx. Postal 37, CEP 37200-000, Lavras - MG, Brazil aut NATIONALLICENCE 773 0- Euphytica Kluwer Academic Publishers 94/2(1997-03-01), 163-168 0014-2336 94:2<163 1997 94 10681 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer